Canvi climàtic estudiat en els fòssils de cavall

Investigadors de l'Institut Català de Paleontologia i de la Universitat d'Utrecht han analitzat l'esmalt de dents fòssils de cavall d'11 a 2 milions d'anys, de les aforesde Terol, Daroca i València. Canvis en la proporció dels isòtops lleugers i pesants de l'oxigen a les dents indiquen que fa 10 milions d'anys (al Miocè superior) la mitjana de temperatures anuals era de 5 ºC més alt que avui dia, i que el clima va refredar-se de llavors ençà. Tanmateix, els canvis isotòpics a les dents reflecteixen els canvis de temperatura en un any, però encara es necessita estudiar més profundament la fisiologia dels cavalls per a reconstruir la magnitud exacta de les amplituds anuals.Investigadores del Institut Català de Paleontologia y de la Universidad de Utrecht han analizado el esmalte de dientes fósiles de caballo de 11 a 2 millones de años de antigüedad hallados en los alrededores de Teruel, Daroca y Valencia. Cambios en la proporción de isótopos ligeros y pesados del oxígeno en los dientes indican que hace 10 millones de años (en el Mioceno superior) el promedio de temperaturas anuales era de 5 oC más alto que hoy en día, y que el clima se enfrió desde entonces. Asimismo, los cambios isotópicos en los dientes individuales reflejan los cambios de temperatura en un año, pero aún se necesita estudiar más profundamente la fisiología de los caballos para reconstruir la magnitud exacta de las amplitudes anuales.Researchers from the Institut Català de Paleontologia and Utrecht University have analyzed the tooth enamel of fossil horse teeth dating from 11 to 2 million years ago near Teruel, Daroca and Valencia. Changes in the proportion of light and heavy oxygen isotopes in the teeth suggest that 10 million years ago (in the Late Miocene) mean annual temperatures were about 5 oC higher than today, and that climate gradually cooled afterwards. In addition, isotopic changes within individual teeth reflect temperature change within one year, but more research on horse physiology is needed in order to reconstruct the exact magnitude of the annual amplitudes

Are Costs of Robot-Assisted Surgery Warranted for Gynecological Procedures?

The exponential use of robotic surgery is not the result of evidence-based benefits but mainly driven by the manufacturers, patients and enthusiastic surgeons. The present review of the literature shows that robot-assisted surgery is consistently more expensive than video-laparoscopy and in many cases open surgery. The average additional variable cost for gynecological procedures was about 1600 USD, rising to more than 3000 USD when the amortized cost of the robot itself was included. Generally most robotic and laparoscopic procedures have less short-term morbidity, blood loss, intensive care unit, and hospital stay than open surgery. Up to now no major consistent differences have been found between robot-assisted and classic video-assisted procedures for these factors. No comparative data are available on long-term morbidity and oncologic outcome after open, robotic, and laparoscopic gynecologic surgery. It seems that currently only for very complex surgical procedures, such as cardiac surgery, the costs of robotics can be competitive to open surgical procedures. In order to stay viable, robotic programs will need to pay for themselves on a per case basis and the costs of robotic surgery will have to be reduced

Late Miocene Erinaceinae from the Teruel Basin (Spain)

Classifying fossil teeth of Erinaceinae (spiny hedgehogs) is a challenging task, because of their scanty record and systematic treatment that heavily relies on skull characteristics. In this paper we describe the complete set of isolated dental elements of Erinaceinae from the upper Miocene sediments of the Teruel Basin (eastern Central Spain). Four different species were recognized: Postpalerinaceus cf. vireti, Atelerix aff. depereti, Atelerix steensmai nov. sp., and a form classified as Erinaceinae genus and species indet. All four are relatively derived in showing multi-purpose dentitions, not showing only adaptations to insectivory, but also to carnivory, herbivory and possibly durophagy/malacophagy. The temporal occurrence of spiny hedgehogs during the middle to late Miocene in the Teruel Basin and neighboring Calatayud-Montalbán Basin peaks within periods of relative aridity, a correlation consistent with modern geographic distribution. Messinian cooling is the best candidate for explaining a remarkable demise of Erinaceinae at 7 Ma

Sleep architecture changes in the APP23 mouse model manifest at onset of cognitive deficits

Alzheimer's disease (AD), which accounts for most of the dementia cases, is, aside from cognitive deterioration, often characterized by the presence of non-cognitive symptoms such as activity and sleep disturbances. AD patients typically experience increased sleep fragmentation, excessive daytime sleepiness and night-time insomnia. Here, we sought to investigate the link between sleep architecture, cognition and amyloid pathology in the APP23 amyloidosis mouse model for AD. By means of polysomnographic recordings the sleep-wake cycle of freely-moving APP23 and wild-type (WT) littermates of 3, 6 and 12 months of age was examined. In addition, ambulatory cage activity was assessed by interruption of infrared beams surrounding the home cage. To assess visuo-spatial learning and memory a hidden-platform Morris-type Water Maze (MWM) experiment was performed. We found that sleep architecture is only slightly altered at early stages of pathology, but significantly deteriorates from 12 months of age, when amyloid plaques become diffusely present. APP23 mice of 12 months old had quantitative reductions of NREM and REM sleep and were more awake during the dark phase compared to WT littermates. These findings were confirmed by increased ambulatory cage activity during that phase of the light-dark cycle. No quantitative differences in sleep parameters were observed during the light phase. However, during this light phase, the sleep pattern of APP23 mice was more fragmented from 6 months of age, the point at which also cognitive abilities started to be affected in the MWM. Sleep time also positively correlated with MWM performance. We also found that spectral components in the EEG started to alter at the age of 6 months. To conclude, our results indicate that sleep architectural changes arise around the time the first amyloid plaques start to form and cognitive deterioration becomes apparent. These changes start subtle, but gradually worsen with age, adequately mimicking the clinical condition

Giffen paradoxes in quantum market games

Recent development in quantum computation and quantum information theory allows to extend the scope of game theory for the quantum world. The paper presents the history and basic ideas of quantum game theory. Description of Giffen paradoxes in this new formalism is discussed.Comment: 12 pages (2 figs), LaTe

Pentylenetetrazole-induced Seizure Susceptibility in the Tau58/4 Transgenic Mouse Model of Tauopathy

In several tauopathies such as Alzheimer's disease (AD), an increased incidence of seizures is observed. Tau, one of the major proteins implicated in AD pathology, is an important regulator of neural network excitability and might participate in the underlying epileptic cascade. However, the mechanisms underlying this relationship are not fully elucidated. We aim to investigate this mechanism by analyzing seizure susceptibility to the convulsant pentylenetetrazole (PTZ) in a novel rodent tauopathy model. A single dose of PTZ was systemically injected in Tau58/4 transgenic mice. To investigate whether young and aged heterozygous (HET) mice exhibit a higher susceptibility to seizures in comparison with wild-type (WT) littermates, video electroencephalography (EEG) in combination with behavioral scoring according to a modified Racine scale was used. The employment of different dosage groups enabled us to characterize the dose range reliably inducing seizures. Here, we report an increased seizure susceptibility in young but not in old HET Tau58/4 mice. Young HET animals displayed more severe seizures and had a reduced latency to the first seizure compared to WTs. Also, age-related differences in susceptibility could be demonstrated for both genotypes. Identification and targeting of secondary diseases such as epilepsy, which aggravate dementia and lead to earlier institutionalization, is key. This study finds that tau pathology itself is sufficient to alter seizure susceptibility in a rodent model, indicating that the disease process is crucial in the emergence of epilepsy in patients with tauopathy

Autonomous Formation Flight using Solar Radiation Pressure

Autonomous formation flight enables new satellite missions for novel applications. The cost and limits of propulsion systems can be overcome if environmental resources are being benefitted of. Currently, atmospheric drag is used in low Earth orbit to this end. Solar radiation pressure, which is of similar order of magnitude as aerodynamic ram pressure, is, however, always neglected. We introduce this force and show that it can be exploited. We demonstrate through simulations that a formation geometry is established quicker if the solar radiation pressure is modeled